On my Fedora KDE install on 40, hibernate is now an available power option. The install has been in upgrade cycles since 35 at this point. I would imagine that barring different DEs showing different power options being a possibility, it is more on detecting hardware compatibility for functional hibernation.
I’d imagine mpd with one of many frontends would work well enough. You’d just need to use a dummy music library directory with symlinks to your four music storages for mpd to pick up and catalog everything.